Revolutionary new cancer treatments won’t be available in many rural areas of the U.S.

Two new cancer treatments have shown miraculous cures, but if you happen to live in Arkansas or Montana, or a handful of other rural states—let alone outside the U.S.—you’ll have to travel hundreds of miles to get them. And it’s by no means certain that they’ll eventually be available everywhere.

These groundbreaking gene therapies, Kymriah and Yescarta, were approved last year in the U.S. Not only are they hugely expensive—Kymriah is $475,000 and Yescarta is $373,000 for a one-time treatment—but for now you can get them only in certain urban areas. We mapped those locations below. (Current Kymriah sites are red; current Yescarta sites are blue; sites where both therapies are available are green; and planned Kymriah sites are orange. Click on the tab in the top left corner to see a drop-down list of all sites.)

As you can see, some of the biggest gaps are in rural states, where cancer already kills more people than it does in cities. That’s a problem because both therapies are given as a last resort when traditional cancer drugs have failed. By the time patients get Kymriah or Yescarta, they’re often very sick, so traveling long distances is hard and could delay treatment.

To be fair, it’s early days and the companies that market the therapies, Novartis and Gilead, have plans to eventually add more sites. But in the short term, some far-flung cancer patients may be out of luck. And even in the long term, there are factors that could limit their access.

Called CAR-T cell therapies, Kymriah and Yescarta involve a highly specialized process. Doctors extract T cells—one of the immune system’s weapons against disease—from patients and genetically alter them, essentially supercharging them against cancer cells. They then infuse the modified immune cells back into the body.

Many patients have had remarkable recoveries, but they can also suffer toxic and sometimes deadly side effects. Aaron Levine at the Georgia Tech School of Public Policy, who has studied the ethics of CAR-T cell therapies, says these side effects will likely be the biggest obstacle to making the therapies more widely available, “as only a small number of physicians and medical teams are prepared to address them.”

If a lot of patients suffer these side effects or die in the initial rollout of Kymriah and Yescarta, that could slow the addition of more sites.

Another factor is that right now, CAR-T therapies primarily treat rare cancers. Currently, Kymriah treats a type of childhood cancer called acute lymphoblastic leukemia, and Novartis thinks only about 600 patients a year will be eligible for it. Yescarta treats large B-cell lymphoma in adults, and Gilead estimates it could help around 7,500 people a year.

“The reality is, the market isn’t that big, so it doesn’t make sense to train everyone to do it,” Levine says. More CAR-T therapies are in development, but so far it’s unclear how well they will work for more common cancers.

There’s also the question of whether insurance will pay for these staggeringly expensive treatments. Only a handful of patients have been treated with Yescarta; hundreds more are waiting because of payment delays. If some insurers decide they won’t cover the cost, that could foil companies’ plans to expand treatment sites. “We need to watch out for a situation in which these therapies only become available to urban elites who live near academic medical centers,” Levine says.

Still, Levine is hopeful. “It’s still early enough for things to change and evolve,” he says.

Peter Emanuel, director of the Winthrop P. Rockefeller Cancer Institute in Little Rock, Arkansas, which is 350 miles from the nearest treatment site for Kymriah or Yescarta, isn’t worried about what the map looks like right now.

He says administering these therapies and managing potential side effects requires a large and specialized team of hospital workers, so it’s probably best—at least for now—that Kymriah and Yescarta are available only at hospitals with more resources.

The real test, says Emanuel, will be if and when new CAR-T therapies are approved for more common cancers. “At that point, I think it’s justified to expand the number of centers, and hopefully that expansion includes smaller cities and more rural states,” he says.

I am MIT Technology Review’s associate editor for biomedicine. I report from Washington, D.C., where I look for stories about how new technology is making us healthier and our medicine better. I am particularly interested in how these advances… More